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Background: Both intracranial atherosclerotic stenosis (ICAS) and moyamoya disease (MMD) are prevalent in Asians. We hypothesized that the Ring Finger protein 213 gene polymorphism (RNF213), a susceptibility locus for MMD in East Asians, is also a susceptibility gene for ICAS in patients whose diagnosis had been confirmed by conventional angiography (absence of basal collaterals) and high-resolution MRI (HR-MRI, presence of plaque). Methods: We analyzed 532 consecutive patients with ischemic events in the middle cerebral artery (MCA) distribution and relevant stenotic lesion on the distal internal carotid artery or proximal MCA, but no demonstrable carotid or cardiac embolism sources. Additional angiography was performed on 370 (69.5%) patients and HR-MRI on 283 (53.2%) patients. Results: Based on angiographic and HR-MRI findings, 234 patients were diagnosed with ICAS and 288 with MMD. The RNF213 variant was observed in 50 (21.4%) ICAS patients and in 119 (69.1%) MMD patients. The variant was observed in 25.2% of patients with HR-MRI-confirmed ICAS. Similarly, 15.8% of ICAS patients in whom MMD was excluded by angiography had this variant. Among the ICAS patients, RNF213 variant carriers were younger and more likely to have a family history of MMD than non-carriers were. Multivariate testing showed that only the age of ICAS onset was independently associated with the RNF213 variant (odds ratio, 0.97; 95% CI, 0.944–0.99). Conclusions: RNF213 is a susceptibility gene not only for MMD but also for ICAS in East Asians. Further studies are needed on RNF213 variants in ICAS patients outside East Asian populations. [ABSTRACT FROM AUTHOR]

Background/Aims: To enable the diagnosis of moyamoya disease (MMD), detection of distal internal carotid artery stenosis and hazy network of basal collaterals (BCs) are required. This study aimed at evaluating the factors that could determine the degree of BCs in patients with angiographically confirmed MMD. Methods: We analyzed 146 consecutive patients with MMD (age 26.2 ± 19.6, range 1–75). The degree of BCs (%) was measured based on conventional angiography. Factors associated with the degree of BCs, including clinico-radiological and genetic factors (p.Arg4810Lys variant), were analyzed. Results: The degree of BCs varied among MMD patients and significantly decreased with an increase in the age of diagnosis of MMD (coefficient –1.55; p < 0.001). Although the degree of BC development depends on the MMD stage (Suzuki stage), it is less prominent in adult-onset (>18 years) MMD compared to childhood MMD. The presence of p.Arg4810Lys variant, types of MMD (bilateral vs. unilateral) and stroke (ischemic, hemorrhagic, or asymptomatic), shrinkage (outer diameter) of intracranial vessels, external carotid collateral status, and cortical neovascularization were not associated with the degree of BCs. Conclusion: Although prominent BCs are required for diagnosis of MMD, BCs are decreased with aging, suggesting that angiogenic capacity is altered in adult onset MMD compared to childhood MMD. [ABSTRACT FROM AUTHOR]

Background: Both Moyamoya disease (MMD) and intracranial atherosclerotic stenosis (ICAS) are more prevalent in Asians than in Westerners. We hypothesized that a substantial proportion of patients with adult-onset MMD were misclassified as having ICAS, which may in part explain the high prevalence of intracranial atherosclerotic stroke in Asians. Method: We analyzed 352 consecutive patients with ischemic events within the MCA distribution and relevant intracranial arterial stenosis, but no demonstrable carotid or cardiac embolism sources. Conventional angiography was performed in 249 (70.7%) patients, and the remains underwent MRA. The occurrence of the c.14429G>A (p.Arg4810Lys) variant in ring finger protein 213 (RNF213) was analyzed. This gene was recently identified as a susceptibility gene for MMD in East Asians. Results: The p.Arg4810Lys variant was observed in half of patients with intracranial stenosis (176 of 352, 50.0%), in no healthy control subjects (n = 51), and in 3.2% of stroke control subjects (4 of 124 patients with other etiologies). The presence of basal collaterals, bilateral involvement on angiography, and absence of diabetes were independently associated with the presence of the RNF213 variant. Among 131 patients who met all three diagnostic criteria and were diagnosed with MMD, three-fourths (75.6%) had this variant. However, a significant proportion of patients who met two criteria (57.7%), one criterion (28.6%), or no criteria (20.0%) also had this variant. Some of them developed typical angiographic findings of MMD on follow-up angiography. Conclusions: Careful consideration of MMD is needed when diagnosing ICAS because differential therapeutic strategies are required for these diseases and due to the limitations of the current diagnostic criteria for MMD. [ABSTRACT FROM AUTHOR]

Abstract: Endovascular embolization has been regarded as the primary treatment for dural arteriovenous fistula (dAVF). The aim of this study was to describe our experience with treatment and outcomes for patients with dural AVF, and to determine optimal treatment modalities. Between November 2007 and March 2011, 43 patients with dAVF (14 cavernous sinus, 20 transverse-sigmoid sinus, and nine patients with other types) were admitted to our Institute for treatment. For cavernous sinus dAVF, transvenous embolization was attempted as the first-line treatment with residual AVF obliterated by transarterial embolization (TAE), except for three patients who were treated conservatively. For transverse-sigmoid sinus dAVF, TAE was the primary treatment method. Nine of 14 (64.3%) patients with cavernous sinus dAVF had complete angiographic resolution. For transverse-sigmoid sinus dAVF, 14 of 17 (82.4%) patients were treated by TAE using Onyx Liquid Embolic System (eV3 Neurovascular, Irvine, CA, USA). Nine of these patients (64.3%) were angiographically cured or improved clinically with no serious complications, and the other five (35.7%) patients showed significant reductions in arteriovenous shunt. The other nine dAVF were treated by TAE or surgical disconnection depending upon the accessibility of the lesion and risk of complications. Six of nine (66.7%) patients had complete angiographic obliteration or clinical improvement. With developments in diagnostic tools and endovascular interventions, dAVF have become an important neurovascular issue. The results of this study suggest that a new approach to treatment of dAVF is needed. [Copyright &y& Elsevier]

Background: This study was undertaken to evaluate the aneurysmal characteristics and clinico-radiological outcomes of unruptured non-branching site aneurysms located on the anterior (dorsal) wall of the supraclinoid internal carotid artery (ICA). Methods: The data of 34 patients that underwent endovascular treatment for 36 unruptured ICA anterior wall aneurysms were reviewed. ICA anterior wall aneurysms were defined as aneurysms that projected superiorly from the anterior wall of the ICA ophthalmic ( n = 35) or communicating ( n = 1) segment on lateral angiograms, without any branch vessel relationship. In addition, aneurysmal characteristics and treatment outcomes were compared with those of 60 unruptured aneurysms originating from the posterior (ventral) wall of the ICA ophthalmic segment. Results: Patients with an ICA anterior wall aneurysm frequently had a mirror aneurysm on the contralateral side (14.7 % versus 3.3 %) or another ICA aneurysm (35.3 % versus 15 %). Two of the 36 ICA anterior wall aneurysms exhibited ICA narrowing suggestive of dissection, and another five had dysplastic ICA dilatation around the neck. Stent-assisted embolization was more frequently performed for ICA anterior wall aneurysms (66.7 % versus 36.7 %) because of unfavorable dome/neck (mean, 1.21) and aspect (mean, 1.15) ratios, and because of microcatheter instability associated with superior aneurysmal projections against the abrupt curvature of the carotid siphon. Procedure-related thromboembolic complications occurred in three patients in the anterior aneurysm group, but no patient deteriorated clinically. Immediate radiological outcomes were more unfavorable for ICA anterior wall aneurysms (residual sac, 36.1 % versus 16.7 %). Nevertheless, rates of recanalization (2.9 % versus 5.2 %) and progressive occlusion (24.7 % versus 8.1 %) during follow-up slightly favored ICA anterior wall aneurysms. Two stent-treated ICA anterior wall aneurysms developed asymptomatic ICA steno-occlusion (8.3 %). Conclusions: Stent-assisted embolization is safe and effective for the treatment of unruptured ICA anterior wall aneurysms exhibiting unfavorable aneurysmal geometries and projections for coil embolization. [ABSTRACT FROM AUTHOR]

Purpose. The aim of the present study was to delineate preoperative factors that may predict perforator injuries following open surgery for an unruptured middle cerebral artery (MCA) aneurysm. Methods. The authors conducted a retrospective review of 85 consecutive patients who underwent surgical clipping of 91 unruptured MCA aneurysms. In addition to demographic profiles, angiographic characteristics of aneurysms, which included the side, size, projection, height from the origin of the ophthalmic artery, and distance between the internal carotid artery (ICA) bifurcation and the aneurysm origin, were analysed and correlated with perforator injuries. Compared with the preoperative CT and/or MRI, any newly-developed infarctions in the striatocapsular area were regarded as perforator injuries even if they were very small and asymptomatic. Results. A perforator injury was found in 14 out of 91 cases (15%%). Although the majority of them remained asymptomatic, neurological deterioration occurred in four patients. Of the analysed variables, both the height (from the origin of the ophthalmic artery) and the distance (between the ICA bifurcation and the aneurysm origin) were significantly associated with perforator injuries. A stepwise increment of the risk was observed as the position of aneurysms became higher or as the distance to the ICA bifurcation became shorter. Conclusions. These results would be helpful in estimating surgical risks for an unruptured MCA aneurysm, one of the most commonly encountered aneurysms in the neurosurgical field. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the clinical course after flow diversion (FD) treatment with a focus on aneurysms with remnant sac filling, by analyzing angiographic outcomes, aneurysm volume, and clinical events. We retrospectively reviewed the medical records of 61 patients who underwent FD for intracranial aneurysms between July 2014 and June 2021. The majority of aneurysms (52.5%) were located in the internal carotid artery, with a median diameter of 16.6 mm and neck size of 9.3 mm. Remnant filling was observed in 17 aneurysms (27.9%) more than 18 months after FD, 10 (16.4%) of these aneurysms underwent enlargement, which occurred only in cases with subtotal filling or entry remnant states. Eleven patients experienced major adverse events, and three exhibited unfavorable functional outcomes. The incidence of major adverse events and unfavorable functional outcomes was significantly higher in the aneurysm enlargement group than that in the no-filling or stable remnant filling groups (P < 0.001). Aneurysmal diameter and the presence of incorporated branches were independent predictors of aneurysm enlargement, while the presence of incorporated branches was the only independent predictor of persistent remnant filling. Aneurysm enlargement after FD is not uncommon, particularly when the aneurysm is large, has incorporated vessels, or does not undergo occlusion within 12 months, often culminating in major adverse events and unfavorable functional outcomes. In addition to investigating angiographic results, it is necessary to evaluate the changes in aneurysm size and clinical events when assessing the efficacy of FD. [ABSTRACT FROM AUTHOR]

Objective We sought to identify the clinical outcome and predictors for ischemic stroke recurrence in adults with symptomatic moyamoya disease (MMD). Methods We analyzed 104 adult MMD patients with ischemic stroke or TIA registered at our institution. All patients underwent digital subtraction angiography and single photon emission computed tomography to measure disease severity and cerebral vascular reserve (CVR). A Cox regression model was used to identify predictors of recurrent ischemic stroke. Results Fifty-nine patients were non-surgically treated and 45 patients were surgically treated. In the non-surgical group, the Kaplan–Meier estimate of ischemic stroke recurrence was 1.6% in the first year and 11.8% in the 5th year. Hypertension (hazard ratio [HR] = 0.07, 95% confidence interval [CI] 0.01–0.99), diabetes (HR = 35.16, 95% CI 2.61–474.16), presence of steno-occlusive lesion in posterior cerebral arteries (HR = 17.53, 95% CI 2.02–152.43), and extended or global decreased CVR (HR = 13.62, 95% CI 1.55–119.84) were independent predictors of recurrence. In the surgical group, the Kaplan–Meier estimate of ischemic stroke recurrence was 24.4% in the first year and 24.4% in the 5th year. Half of the recurred patients experienced recurrent ischemic strokes postoperatively. Diabetes was the only predictor of recurrent ischemic stroke (HR = 6.17, 95% CI 1.31–29.14). Conclusions In non-surgically treated MMD, PCA stenosis and CVR were identified as predictors of ischemic stroke recurrence. Diabetes was an independent predictor of recurrent ischemic stroke in both non-surgical and surgically treated MMD groups. [ABSTRACT FROM AUTHOR]